"Disturb" "disquiet," "perturb," "agitate" and "fluster" mean to cause someone to be upset, angry, or worried. "Disturb" implies interference with someone's mental processes caused by worry, perplexity, or interruption, as in "I was disturbed by her behavior." "Disquiet" suggests loss of sense of security or peace of mind, as in "We were disquieted by the news of what happened." "Perturb" implies deep disturbance of mind and emotions, as in "It perturbed her that he had come home so late." "Agitate" suggests obvious external signs of nervous or emotional excitement, as in "He was so agitated that he couldn't concentrate on his work." "Fluster" means to make someone nervous and unsure, as in "The speaker was flustered by my question."